Lock nut



July 14, 1931. c, G, OLSON 1,813,947

LOCK NUT I Filed Oct.' 11, 1928 kagz (Jig

Patented July 14, 1931 UNITED STATES PATENT OFFICE CARL G. OLSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO SHAKEPROOF LOCK WASHER COM PANY,OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE 'LOCK NUT Application filed October 11, 1928. Serial No. 311,743.

My invention relates, to lock nuts and particularly to lock nuts of the twisted tooth type.

My present invention is predicated upon subject matter simulating that set forth in my co-pending application Serial No. 291,- 739, filed July 11, 1928, but is an improve ment on the structure disclosed in said application. In said application I have disclosed a lock nut provided with a plurality of marginal twisted teeth and a recess or cut along the inner margin of said nut to permit of its being helically formed for application to the threads of a member to be secured, this recess 'or out being provided at the point where the nut straddles the thread. By providing the recess along the inner margin as described, some of the stock is necessarily removed or severed with the result that the body portion of the WLSller may be somewhat weakened at that point.

One of the primary objects of my present invention is to pr0vide a lock nut of the marginal twisted tooth type which is not weakened as the result of the forming thereino'f a recess or cut to permit said nut to be helically formed for application to a threaded member. 7

More specifically, it is an object of my present invention to effect the strengthening of the lock nut above set forth'by providing additional stock adjacent the point at which the body 'portion of the nut is cut.

Still more specifically, my invention contemplates the provision of a lock nut of the instant nature which is uniform in strength, and to this end I propose to provide an unbroken section of stock for a predetermined distance along the outer margin of the nut adjacent the .cut or recess formed along the inner margin-of the nut.

These and other objects will be more apparent from the following detailed description when considered in connection with the accompanying drawings, wherein- Figure 1 discloses a lock nut formed in accordancewith the teachings of my present invention, said nut being disclosed in operative association with a fragmentary portion of an electrical outlet box;

' numeral 10.

,1; and

' Figure 4 is a detailed perspective view of the lock nut shown in Figures 1 to 3 inc'lusive.

Referring now to the drawing wherein like numerals have been employed to designate similar parts throughout the various figures, it will be observed that one embodiment of my invention comprises a lock nut which I have indicated generally by the 'This lock nut comprises a body portion 12 and a plurality of marginal twisted teeth 14 formed integral with the body portion 12. These teeth are twisted in a direction so as to cause the same to lockingly grip or dig into a surface against which the nut may be tightened. A recess or cut 16 is provided along the inner margin of the body portion 12 and this recess serves to permit said body portion, when helically formed, to be applied to the threads ofa member toJoe secured, as for example, the threads of a conduit 18, Figures 1 and 3. In Figures 1 and 3' the lock nut is shown as being tightened against the inner surface of an outlet box 20, the corners of the twisted teeth which project out of the plane of the body serving in this instance to prevent the unscrewing of the nut.

Reference is now made to a marginal section 22 of the lock, nut 10 which is formed at a point adjacent the recess or cut 16.

This section 22 provides a continuous marginal stock portion which serves to compensate for any weakness in the nut body which may be occasioned by the presence of the recess 16. It is very desirable to provide a lock nut of the type shown which is uniformly rigid, that is to say, a lock nut, the strength of which is unimpaired by any cuts or recesses formed along the inner margin thereof.

A look nut of the type described may be conveniently stamped, cut or otherwise formed from'flat stock. This lock nut serves as a very effective means for securing parts together such for example as the outlet box elements which are disclosed. Although said nut is relatively light in construction, the binding or looking eflectiveness thereof is sufficient to withstand considerable and continued vibrations which would ordinarily be sufficient to cause threaded nuts of conventional design and of considerable size to be loosened. By providing the additional stock adjacent the recess on the inner margin of the nut, said nut may be tightened against a member without the slightest possibility of breakage at the point where said recess is formed. This additional stock or section serves also to sufficiently strengthen the nut adjacent the recess formed therein so as to prevent breakage or severing thereof in the event that said nut is subjected to hard usage, vibrations or other forces which might have a tendency to subject the same to unusual strains and stresses. In other words, by forming the marginal portion of the nut with this section for a predetermined distance opposite to the recess, this portion of the nut is strengthened to substantially approximate the strength at all other points. A convenient spanner wrench of conventional design (not shown) or any other convenient tool such as a screw driver may be employed to engage the teeth and thereby cause the same to be effectively tightened against the work.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A look nut formed from flat spring stock including an annular body portion, a plurality of prongs extending radially from and spaced along the outer margin of said body portion, said prongs being warped out of the plane of said body portion to present work engaging teeth, said annular body portion being severedradially so as to permit the inner margin of said body portion to form a helix, which conforms with the thread helix of the element to whichit may be applied, and a strengthening member formed along the outer margin of said body portion adjacent the severed section thereof, the width of said member being substantially greater than the width of an individual prong, said member extending on opposite sides of the severed portion of the body and thereby rendering the portion of said body adjacent said severed area substantiall as strong as the' remaining portion thereo 2. A look nut. formed from flat spring stock including an annular body portion, a plurality of prongs extending radially from and spaced along the outer margin of said body portion, said prongs being warped out of the plane of said body portion to present work engaging teeth, said annular body portion being severed radially a distance substantially equal to the width of said body portion adjacent one of the prongs so as to permit the inner margin of said body portion to form a helix, which conforms with the thread helix of the element to which it may be applied, and a strengthening member formed along the outer margin of said body portion adjacent the severed section thereof, the width of said member being substantially greater than the width of an individual prong, said member extending on opposite sides of the severed portion of the body and thereby rendering the portion of said body adjacent said severed area substantially as strong as the remaining portion thereof.

In witness whereof, I have hereunto subscribed my name.

CARL G. OLSON. 

